Railway crossing signal



Nov. 19, 1935. F. B. WIEGAND RAILWAY caossmexsmmt.

Filed Oct. 9, 1930 AT ORNEY.

Patented Nov. 19, 1935 TES UNITED RAILWAY CROSSING SIGNAL Frederick E. Wiegand, Cleveland, Ohio, assignor,

by mesne assignments, to General Railway Signal Company, Rochester, N. Y.

Application October 9, 1930, Serial No. 487,397

16 Claims.

This invention relates in general, to railway signal systems, and has more particular reference to one adapted for use in controlling highway crossing signals and the like.

It has, for one object, to provide a signal which is operated for a predetermined time on the approach of a train, regardless of the speed of the train.

Another object of the invention is to provide a signal device controlled by a timing mechanism in combination with the approach of a train whereby the time of operation of the signal device is modified by the speed of a train.

Another object of the invention is to provide a signal device controlled by the approach of a train and controlled by a timing mechanism, and in which the train, on a predetermined portion of the track, operates the timing mechanism away from the controlling position.

Other objects, purposes and features of the invention will be more particularly understood from the following specification and the accompanying drawing, given solely for the purpose of illustration. In the drawing:-

5 Fig. l is a wiring diagram showing the application of the invention for controlling a highway crossing signal.

Fig. 2 is a view of the timing device used in Fig. 1.

30 Fig. 3 is a detail of the timing device.

Fig. 4 is a wiring diagram of a modified form, corresponding to Fig. l, but using a different type of time controlling device.

The established practice in the application of 35- highway crossing signals, is to provide a signal at the crossing in the form of an electric bell, a light signal or a combination of these devices which is controlled and brought into operation by a track circuit at the approach of the crossing, so

40 that a train passing over this track circuit establishes the operating circuit of the signal, thereby giving warning of an approaching train.

The track circuit referred to must be of such length that the highest speed trains will operate 45 the crossing signal for an interval of time suflicient to enable traffic to clear the crossing. When slow speed trains are run on the same track it is apparent that they will occupy the track circuit controlling the highway signal for a longer inter- 50 val of time than the high speed trains with the result that the crossing signal tends to delay trafiic unnecessarily and to encourage using the crossing when the warning signal is operating.

It is apparent that if the crossing signal is operated for a substantially uniform interval of time for all classes of trains, and this time interval is properly adjusted so that traflic may clear the crossing and may not be unnecessarily dey there W ll be a more wholesome respect for the crossing signal and the movement of traffic will be considerably facilitated.

This result is obtained in the present invention by providing a controlling mechanism for the signal device which is operated by the train on an 5 approaching track circuit of predetermined length. The time which the train occupies this predetermined length of track circuit is used as a measure of its speed and to operate the controlling mechanism in accordance therewith, so 10 that the signal device is ultimately operated in accordance with train speed.

In practice, these results are obtained by providing on the trackway a pair of adjoining track circuits preceding the location of the signal device. The first track circuit encountered is of a predetermined length and operates a timing device which controls the signal device away from the controlling position. When the next track circuit is encountered the conditions are established to restore the timing device to the controlling position and to operate the signal device. It will thus be understood that if a train passes over the predetermined or measured track circuit at high speed, the timing device will be operated away from the control position for a short interval of time and is restored back to the controlling position after a corresponding short interval of time. On the other hand if the train speed is slow on the measured track circuit, the 3,0 timing device is moved away from the controlling position for a greater interval of time and a correspondingly greater interval is necessary to restore it to the controlling position when this train enters upon the second track circuit. In practice, this enables the signal device to be operated with respect to the speed of the approaching trains, and to be operated for an interval of time that is substantially the same for all trains.

A system of the type disclosed in this invention is frequently applied in combination with block signal systems which use track circuits for controlling the signals. Where the same track circuits are used for controlling a highway crossing signal by the present invention, it is not always possible to make the predetermined track circuits of uniform length, with the result that the track circuit at one location may be much longer than at another location. These conditions are readily provided for by making the timing device adjustable in its operation, and by making it respond to a different element of time when moving in one direction from that necessary to move it in the reverse direction.

In the drawing, II and I2 are track rails and 5 is, are insulated joints dividing the track rails into track circuits A and B, approaching a highway crossing C. The tracl: circuit A, is provided with a track battery I5, at one end and with a track relay M at the other end, and the track circuit B is provided with a track battery I! at one end, and with a track relay l6, at the other end, in accordance with standard practice.

A line relay 2?, is controlled from. a battery 2!, through wire 22, contact 23 of relay 4, in the d-eenergized position, wire 24, contact 25 of relay 6 in the energized position, wire 23, relay 2! and wire 28 to battery 2 I Relay 21, thus remains in the deenergized position, except when relay I4 is deenergized and relay i8 is energized, that is, except when a train is occupying the first track section A, and when the second track section B is unoccupied.

A relay 3|, is controlled from battery wire 22,

through contact 29, of relay l6 energized, wire 38, relay 3|, and wire 28 to battery 2 so that relay 3| is maintained in energized position except when relay 5 is deenergized, that is, except when a train is occupying section B.

When the relay 2! is energized, a controlling magnet 34 of the timing device is energized from battery wire 22, through contact 32, of relay 21, in the energized position, wire 33, magnet 34, and. wires 28, 28 to battery 2|. When magnet 34 is energized a lever 35, pivoted at 38, is pulled down for engaging a mercury tube 38, at 31 and moving this tube on its mounting at 39, to the horizontal position indicated in Fig. 2, this movement being opposed by a spring 43, connected to the tube by a collar 42.

The tube 38 is partly filled with mercury, as indicated at 4|, and when in the position shown, establishes a circuit from the battery wires 22, 22' through the mercury to wires 44, and 45, and by either of these wires through switch 46, and wire 41, to the crossing signal 48, and from this signal by wire 49, and contact 50 of relay 3| in the deenergized position, to wire 28 and battery 2|. It will be observed from Fig. 2, that when the tube 38, is tilted by the lever 35, to the horizontal position the circuit between the wire 22, and wires 44, and 45 is interrupted.

The how of the mercury from one end of tube 38, to the other end may be controlled by a restricted orifice, as indicated in Fig. 3, in which 5| is a barrier in the tube having an orifice at 52, to permit the flow of mercury at a predetermined rate from one end of the tube to the other, thereby establishing the time interval of the device. When it is desired to permit the flow of the mercury in one direction at a greater rate than in the opposite direction, the ball valve 53 or its equivalent may be used as indicated which valve partly closes the orifice in one direction, and leaves it free in the opposite direction. 4

The operation of the system described will b understood by considering the approach of a high speed train in the direction of the arrow towards the crossing C. The track section A is of a predetermined length, and a train on this section will energize relay 21, and tilt the mercury tube 38, for a period of time equal to the time that the train takes in running over the measured section A. During this time, the mercury has been flowing away from the terminals of wires 44 and 45, in the tube, and when this same train enters the track section B, and deenergizes relay I6, relays 21 and 3|, are thereby deenergized. This deenergizes magnet 34, releasing lever 35, and permitting spring 43 to move the tube 38, to the normal position. As soon as mercury has flowed into the opposite end of tube 38 to complete the circuit between wire 22, and wire 44 or 45, the circuit of the signal device 48 is thereby established, and the signal is brought into operation.

In this operation it will be noted that the circuit of the signal device 48 is not established until the return of the mercury in the tube 38 to the 'normal position, and the time required for this mercury to return depends upon the length of the 5 track section A and the time the train occupies this section and also the retardation that may be set up to the flow of the mercury in this direction by the ball valve 53. The switch 46 may be used to vary the time interval in which the device 1 operates. It is apparent from the drawing that the circuit to wire 45 which is located in the lower part of the tube, will be closed before the circuit to wire 44 which is located above wire 45. When switch 45 is in the position shown a longer 1 time interval is necessary for starting the indication oi the crossing signal than when this switch is connected to wire 45.

From this operation it will be noted that the speed of the train is determined by the time the 2 train occupies section A, and that the operation of the signal device by the train in the second section B, is modified by the speed of the train. Hence a high speed train occupies section A, for

a short interval of time and the timing device 38 2 is restored to the normal position after a short interval of time while, on the other hand, a slow speed train occupies section A, for a longer interval of time, and the device 38 requires a longer interval of time to bring it to: the operating posi- 3 tion. When these intervals of time are applied to the trains travelling in section B, the result is that the crossing signal is brought into operation at substantially the same interval of time before the trains reach the crossing, without re- 3 gard to the speed of the trains.

It should be observed that in the normal position as shown in Fig. 1, the mercury in tube 38 closes the operating circuit of the crossing signal; and thus should the timing mechanism fail to 4 operate when a train enters track section A, there will be noimproper operation of the system except that the timing device will not function, and the crossing signal will operate for a longer interval of time (the signal commencing to operate im- 4 mediately upon the entry of the train into block B.) Thus by biasing the timing device to the controlling position the closed circuit principal is maintained throughout.

The arrangement in Fig. 4 is similar to that 5 shown in Fig. 3, with respect to the circuits involved, but an electric timing device is employed comprising a motor 6|, connected through gears 62 and 63, to a disc 84 which is held in 2, normal position by a stop 65, and is rotated in the 5 direction of the arrow by the motor 8| to wind up a spring 66, which is anchored at 81. This disc carries a contact segment 88 engaging con tact fingers 53, whereby a circuit is established from the battery wires 22, 22' through segment 6 68 to wire 78, and by contact 58 of relay 3!, in the deenergized position, to wire H and signal device 48, and thence by wire 28, to battery 2| When relay 21 is energized, the circuit of motor 8| is established from battery wire 22 6 through contact 32, wire 13, motor 8|, and wires 28 and 28 to battery 2|. This starts and operates the motor 5|, as long as a train occupies track section A, and through the train of gears the segment 68 is moved away from the contact fingers 39, thereby opening the circuit of the signal device 48. A friction drive may be in troduced on the gear 53, so that if a train should stop on section A, and continue to drive motor 7 61, beyond the limits of movement of disc 64, this clutch would release the connection.

When relay 2! is deenergized, motor 6| is short circuited through adjustable resistance 14, contact 32, wire 13, motor 6|, and wire 28. As soon.

as a train enters section B, it deenergizes relays 21 and 3|, whereupon spring 66, rotates disc 64, in the reverse direction and through the train of gears rotates the armature of motor Si, in the reverse direction, but this motor being short circuited through resistance 14, a dynamic braking efiect is produced, the degree of which can be regulated by the resistance 14, and hence the time in which the disc 64 returns to the normal position can be regulated. The segment 68 is made of a length that will interrupt the circuit at 69 after a predetermined movement of the motor 6!, and this length may be regulated to suit conditions.

It will be noted that the operation of the mechanism in Fig. 4, corresponds with the operation of the mechanism in Fig. 1, but in Fig. 4 the disc 64 is biased by spring 66, to the normal controlling position, and is moved away from this position by motor 6i when a train occupies section A, and of course is moved towards the controlling position by spring 66 when a train occupies section B. The distance that the disc 64 moves away from the controlling position is determined by the time the train occupies section A, and the time it takes to move back before closing the circuit at '69 is determined by the retardation of the motor armature which retardation is adjustable by resistance M, and in this way, the

'- time that elapses after a train has entered section B, and before operating the signal, is determined.

It should be understood that this invention may be applied in a variety of forms additional to those shown in the drawing, and that other types of timing mechanisms may be used in applying the invention. 7

Having thus described my invention, I claim:

1. In a railway signal system, in combination, a railway track, a pair of adjacent track circuits formed by the rails of said track, a signal device located on the trackway and energized when one of said track circuits is occupied by a train, a timing device normally standing in a position to energize said signal device in cooperation with said track circuit and means operated by the other track circuit as a train moves thereover for moving said timing device away from said energizing position.

2. In a railway signal system, in combination, a railway track, a first and second track circuit formed by the rails of said track, an electric signal device located on the 'trackway, a timing device operating said signal device by closing its circuit in the normal position of said timing device, means operated by said first track circuit as a train passes thereover for operating said timing device away from the operating position and means operated by said second track circuit for permitting said timing device to move to the normal position. I

3. In a railway crossing signal, in combination, a first track circuit of a predetermined length having a track relay, a second track circuit having a track relay, said track circuits formed by the rails of the track and said track relays being normally energized and being deenergized when the respective track circuits are occupied by a train, a signal device on the trackway, a timing device, a relay controlled by the track relay of said second track circuit and being de'energized during the time said track relay is deenergized, said relay and said timing device operating said signal device by closing its circuit and means including said first track relay for operating said timing device in accordance with the time a train occupies the first track circuit for determining the starting of operation of said signal device after the train enters said second track circuit.

4. In a railway signal system, in combination, a railway track divided into sections to constitute track circuits, a signal device located on the trackway, a timing device controlling said signal device and when in the normal position establishing the circuit of said signal, means controlled by said track circuits for moving said timing device into position to operate said signal device and into position to prevent the operation of said signal device and means whereby the movement of said timing device to one position is retarded with respect to its movement to the other position.

5. In a railway signal system, in combination, a railway track divided into sections by track circuits, each having a track relay, each track relay being normally energized and being deenergized by the presence of a train in the respective sections, a signal device located on the traclrway, a timing device, a relay, a circuit for said relay established through the front contact of one of said track relays and being deenergized during the time said track relay is deenergized, said relay in the deenergized position and said timing device establishing the circuit of said signal device, means for moving said timing device into position to operate said signal device and means for adjusting the time of operation of said timing device.

6. In a railway signal system, in combination, a railway track divided into sections by a first and a second track circuit, each having track relays, each track relay being normally energized and being deenergized by the presence of a train in the respective sections. said first track; circuit being of a predetermined length, a signal device located on the trackway, a circuit for said device, means controlled by the relay of said second track circuit as long as this circuit is occu pied by a train for establishing the circuit of said signal device and a timing device operated by the track relay of said first track circuit, said timing device establishing the circuit of said signal device in co-operation with said means, whereby the time of operation of said signal de vice is controlled by the speed of the train on said first track circuit.

7. In a signal system, in combination, with a pair of adjacent track circuits and a signal, means for energizing the signal when one of the circuits is occupied, a timing device normally in condition to energize the signal in cooperation with said one track circuit, and means controlled by the occupancy of the other track circuit for changing the timing device away from its normal condition, andmeans for automatically restoring the timing device to its normal condition upon .said other track circuit becoming vacated.

occupancy of the other track circuit for changing the timing device away from its normal condition, and means, including adjustable means, for automatically restoring the timing device to its normal condition, at predetermined rates, upon said other track circuit becoming vacated.

9. In a signal system, in combination, with a pair of adjacent track circuits and a signal, means for energizing the signal when one of the circuits is occupied, a timing device normally in condition to energize the signal in cooperation with said one track circuit, and means controlled by the occupancy of the other track circuit for changing the timing device away from its normal condition, and'mcans for automatically restoring the timing device to its normal condition upon said other track circuit becoming vacated, said timing device including a tiltable tube, contacts in the tube, and a conducting fluid in the tube.

10. In a signal system, in combination, with a pair of adjacent track circuits and a signal, means for energizing the signal when one of the circuits is occupied, a timing device, including an electrically operated contactor normally in condition to energize the signal in cooperation with said one track circuit, and means controlled by the occupancy of the other track circuit for changing the timing device away from its normal condition, and means, involving adjustable means, for automatically restoring the timing device to its normal condition, at predetermined rates, upon said other track circuit becoming vacated, said timing device including a tiltable tube, contacts in the tube, and a conducting fluid in the tube.

11. In a signal system, in combination, a stretch of railroad track divided into sections, a track circuit in each section, a signal at the track, one of saidtrack circuits and a timing device jointly controlling the signal, means biasing the timing device to a normal position in which it closes the circuit of the signal, an electric motor controlled by the track circuits for moving the timing device into a position to prevent closing the signal circuit, and means for retarding movement of the timing device.

12. In a signal system, in combination, a stretch of railroad track divided into sections, a track circuit in each section, a signal at the track, one of said track circuits and a timing device jointly controlling the signal, means biasing the timing device to a normal position in which it closes the circuit of the signal, an electric motor controlled by the track circuits for moving the timing device into a position to prevent closing the signal circuit, and adjustable current limiting means for retarding the movement of the timing device toward circuit closing position relatively to its movement away from circuit closing position.

13. In a signal system, in combination with a pair of adjacent track circuits and a signal, means for energizing the signal when one of the circuits is occupied, a timing device normally in condition to energize the signal in cooperation with said one track circuit, and means controlled by the occupancy of the other track circuit for changing the timing device away from its normal condition, and means for automatically restoring the timing device to its normal condition upon said other.

track circuit becoming vacated, said timing device including a tiltable container, a conducting fluid in the container, a plurality of spaced contacts in the container arranged to be bridged by the fluid when the container is in its normal conpancy of the other track circuit for changing the timing device away from its normal condition, and means for automatically restoring the timing device to its normal condition upon said other track circuit becoming vacated, said timing device including a tiltable container, a conducting fluid in-the container, a plurality of spaced contacts in the container arranged to be bridged by the fluid when the container is in its normal condition and a dividing wall in the container forming a space containing the contacts and a space having no contacts, with the wall having a constricted opening therethrough, and a check valve in the constricted opening.

15. In a signal system, in combination, with a pair of adjacent track circuits and a signal, means for energizing the signal when one of the circuits is occupied, a timing device normally in condition to energize the signal in cooperation with said one track circuit, and means controlledby the occupancy of the other track circuit for changing the timing device away from its normal condition, and means for automatically restoring the timing device to its normal condition upon said other track circuit becoming vacated, said timing device including a tiltable container, a conducting 'fluid in the container, a plurality of spaced contacts in the container arranged to be bridged by the fluid when the container is in its normal condition and a dividing wall in the container forming a space containing the contacts and a space having no contacts, with the wall having .a constricted opening therethrough, said spaced contacts including a common contact and a plurality of other contacts, and means for selectively placing the common and one of said other, contacts, in control of energizing the signal.

16. In a signal system, in combination, with a pair of adjacent track circuits and a signal, means for energizing thesignal when one of the circuits is occupied, a timing device normally in condition to energize the signal in cooperation with said one track circuit, and means controlled by the occupancy of the other track circuit for changing the timing device away from its normal condition, and means for automatically restoring the timing device to its normal condition upon said other track circuit becoming vacated, said timing device including a tiltable container, a conducting fluid in the container, a plurality of spaced contacts in the container arranged to be bridged by the fluid when the container is in its normal condition and a dividing wall in the con tainer forming a space containing the contacts and a space having no contacts, with the wall having a constricted opening therethrough, and a check valve in the constricted opening, said spaced contacts including av common contact and a plurality of other contacts, and means for selectively placing the common and one of said other,.contacts, in control of energizing the signal.

FREDERICK B. WIEGAND. 

